Update vitreum (#946)

- Updates Vitreum to v6.0.1 + some custom fixes.
  - Stylesheets must be imported with `require('./sheet.less');` but can also can now share stylesheets between jsx components.
  - Should eliminate a lot of security concerns with older nested dependencies.
  - Changed a lot of files to make this work
- Also removes dependency on PicoRouter in favor of React-Router

scripts/buildAdmin.js

@@ -0,0 +1,31 @@
+const fs = require('fs-extra');
+const Proj = require('./project.json');
+
+const { pack } = require('vitreum');
+const isDev = !!process.argv.find((arg)=>arg=='--dev');
+
+const lessTransform  = require('vitreum/transforms/less.js');
+const assetTransform = require('vitreum/transforms/asset.js');
+//const Meta = require('vitreum/headtags');
+
+const transforms = {
+	'.less' : lessTransform,
+	'*'     : assetTransform('./build')
+};
+
+const build = async ({ bundle, render, ssr })=>{
+	await fs.outputFile('./build/admin/bundle.css', await lessTransform.generate({ paths: './shared' }));
+	await fs.outputFile('./build/admin/bundle.js', bundle);
+	await fs.outputFile('./build/admin/ssr.js', ssr);
+	await fs.outputFile('./build/admin/render.js', render);
+};
+
+fs.emptyDirSync('./build/admin');
+pack('./client/admin/admin.jsx', {
+	paths : ['./shared'],
+	libs  : Proj.libs,
+	dev   : isDev && build,
+	transforms
+})
+	.then(build)
+	.catch(console.error);